Fuel pump



Aug. 26, 1941. H. Q EbwARDs 2,254,174

FUEL PUMP Filed June 13, 1958 `2 Sheets-Sheet 1 4M @MA/ada,

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Aug. 26, 1941.

H. c.. EDWARDS FUEL PUMP Filed June 13. 41938 2 sheets-sheet 2 Patented Aug. 26, 1941 UNITED STATE-s f PATENT OFFICE iabraas'slmgmrr remata I h10,y a corporation of Ohio l l Application June 13, 1938,'Sel'ial No. 213,323 somma. (cima-201) 'I'his invention relates to pumps, particularly to diaphragm pumps of the kind operated by or in unison with the internal combustion engine for supplying fluid fuel to a charge forming device thereof. The principal object of the invention is to provide 'manually operable means for priming and flushing the pump that is simple and easy to operate, readily accessible and of simple and economical construction.- The Invention consists in the pump and in the construction,

combinations and arrangements of parts hereinafter described and claimed. i

In the accompanying drawings, which form part of this speclcation and wherein like symbols refer to like parts wherever they occur,

Fig. 1 is a plan view of a pump embodying my invention,

Flg.,2 is a side view of said pump, A Fig. 3 is a central section on the line 8-3 of Fig. 1, showing the pump mounted on a housing containing a cam for actuating said pumpand the manually operable priming. means in inoperative position, Y

Fig. 4 is a section on the line H of Fig. 3:

and

, per section containing the inlet and outlet pas- Fig. 5 is a section similar to' rig. s, showing the' manually operable priming means in operableposition.

The pump shown in the accompanying drawings comprises a sectional casing A having a vertically disposed attaching plate or ange I that is removably secured by` cap screws 2 to the Avel'- tical face of the housing B of the fuel injection pump for a Diesel engine, said housing contain` ing a power driven shaft I having a cam I thereon for operating a pump mechanism enclosed within said casing. Said casing has two chambers formed therein. a lower chamber 8, which contains the pump actuating mechanism and opens into the'housing B 'through an opening i formed therein opposite the cam shaft l, and an expansible upper chamber 'I with a contained impeller in the form 'of a deformable wall 8 of.

flexible material, whereby the volumetric content of said expanslble chamber may be successively increased and diminished by movement of said deformable wall or diaphragm. v

Located in the pump casing A, above the pump vchamber l are inlet and outlet valve chambers 8 and I0 that communicate with said pump housing through ports Il and I2 extending through a partition I3 whichv separates said valve chambers from said pump chamber.v The inlet valve chamber 9 is provided with an inwardly opening valve means of a spring I 8 interposed between said valve and the partition Il: and the outlet valve chamber III is` provided with a valve I 8 which covers the outlet port I2 in said partition and is sageway I8 leads inwardly fromI one side of the l casing A to the inlet valve chamber 9A and is connected at its outer end to a suitable supply pipe 20. Leading outwardly from the outlet valve-L chamber I0 through the other side of the casing A is an outlet passageway 2l 4that is connected at its outer end with a suitable outlet ordischarge pipe 22..

For convenience Jin manufacture, the casing A" is made in upper and lower sections 23 land 24, respectively, that aresecui'ed together with the marginal portion of the diaphragm 8 clamped A therebetween by means of cap screws 25, the upsageways and valve chambers and the vlower section containing the mechanism for operating-the diaphragm. Said mechanism comprises a stem 28 projecting downwardly from the diaphragm 8 axially thereof, a coil compression spring 21 surner arm loosely engaging an elongated slot Il provided therefor in the lower portion of said stem and with its outer arm extending into the housing B through the opening 8 thereof vand bear- 111g against the cam 4 therein. By this arrangement, when the rise of the cam cooperates with the outer arm of the oscillatory lever 29, the inner arm thereof pulls the diaphragm 8 downwardly, thereby causing fluid to be drawn into the pump chamber l through the inlet valve Il, and when the rise of said cam moves out of contact with said lever, the inner'arm thereof'swings upwardly, thus permitting the compressed spring 2l to expand and force said diaphragm upwardly andV force the fluid out of said pump chamber through the discharge valve I8. The elongated slot 3| in the stem 26 of the diaphragm 8 permits continued eperation of the lever 28 by the ca'm I when the pressure in the pump chamber l l ating the1ever 2s when it is desired to prime or u which is yieiqably held against its seat by 'ilush the pump. Said means comprises a rod 82 mounted for reciprocating movement in the upper or cover section 23 of the pump casing A. This rod has one end located exteriorly of the casing and provided with an operating knob 33 and has its other end disposed in the chamber in the lower section 24 of the casing A and extending through an elongated slot 3l in the long arm of the lever 29 and terminating beneath said arm in a head 35 adapted lto abut thereagainst. A coil spring 36 has one end seated in a recess 31 in said casing and its other end seated in a recess 38 provided therefor in the long arm of said lever, said spring tending to urge said arm in the direction of the cam 4 and the headed end 35 of the manually operable rod 32. The reciprocable rod 32 is releasably held in-its innermost position by means of a leaf spring 39 which is secured to the casing A and has a free end adapted to snap over a peripheral rib 40 on the operating knob 33.

By the arrangement described, the pump may be manually operated by reciprocating the rod 32, the outward movement of the rod causing the headed inner end 35 thereof to bear against the long arm lever 29 and thus cause the short arm thereof to pull the diaphragm 8 downwardly, while the spring 21 serves to force the diaphragm upwardly and operate the lever to draw the rod inwardly. In the event that the pressure in the pump chamber 1 is sucient to prevent expansion of the diaphragm operating spring 21, the lever 29 is actuated by the smaller spring 36 to draw the rod inwardly, the elongated lever receiving slot 3| in the stem 26 of the diaphragm permitting such movement of the lever. The manually operable rod 32 is preferably disposed at a diverging angle to the vertical face of the housing B, thereby making the rod readily accessible for easy operation. In the inoperative position of said rod, the headed inner end 35 thereof is located in the housing B where it is yentirely clear of the lever 29 during the mechanical operation thereof. In such position of the rod any oil that accumulates thereon during the mechanical operation of the pump will drain off the headed inner end of said rod into the cam chamber of the housing B.

While I have shown and described my pump in connection with a fuel injection pump, it is obviously applicable to other devices.

What I claim is:

1. In a pump, a casing having a chamber, a diaphragm forming a deformable wall of said chamber, and having a stem with a transverse opening, a coil compression spring surrounding said stem between said diaphragm and a seat provided therefor in said casing for moving said.

diaphragm in one direction, mechanically operated means for moving said diaphragm in the other direction comprising a lever mounted in said casing for oscillatory movement on an axis disposed transversely of said stem with one arm loosely engaging the opening therein, a rotary c'am engaging the other arm of said lever for swinging the same in a direction that will move said diaphragm against the pressure of said spring, a member reciprocable in said casing transversely of said lever axis with its outer end located exteriorly thereof for manual operation, the inner end portion of said member extending loosely through an opening provided therefor in said other arm of said lever and terminating in a head larger than said opening, and a spring mounted in said casing for urging said other arm in the direction of the head at the inner end of said member.

2. In a pump, a casing having a pump chamber, a diaphragm forming a deformable wall of said chamber and having a stem with a transverse opening, a coil compression spring surrounding said stem between said diaphragm and a seat provided therefor in said casing for moving said diaphragm in one direction, a lever mounted in said casing for oscillatory movement on an axis disposed transversely of said stem with one arm disposed in the transverse opening therein, a rotary operated cam engaging the other arm of said lever for swinging the same in a direction that will move said diaphragm in the other direction, and a member reciprocable in said casing transversely of said lever axis with the outer end located exteriorly thereof for manual operation, the inner end portion of said member extending loosely through an opening provided therefor in said other arm of said lever and terminating in a head larger than said opening, said openings in said stem and said other arm of said lever being elongated to permit said lever to oscillate when said spring is compressed and said member is in its innermost position, anda spring mounted in said casing and bearing against said other arm of said lever for urging the same in the direction of the head at the inner end of said member.

3. In a pump, a casing having a chamber and a contained impeller, a spring for moving said impeller in one direction, a lever pivoted in said casing with one arm operatively connected to said impeller for moving the latter in the other direction, a cam in operative relation to the other arm of said lever for swinging the same in a direction that will move said impeller in said other direction and independently manually operable means engageable with said other arm of said le.. ver for swinging the same in the same direction as said cam swings it.

4. In a pump, a casing having a chamber and a contained impeller, a spring for moving said impeller in one direction, a lever pivoted in said casing with one arm operatively connected to said impeller for moving the same in the other direction, and independently operable mechanically and manually operable means both engageable with the other arm of said lever for swinging the same in a direction that will move said impeller in said other direction, said mechanically operable means comprising a rotary cam engaging said other arm of said lever, and said manually operable means comprising a member reciprocable in said casing transversely of the axis of said lever with its outer end portion located exteriorly of said casing and with its inner end portion extending loosely through an opening provided therefor in said other arm of said lever and terminating in an enlargement adapted to bear against the cam opposing face of said other arm of said lever.

5. In a pump, a casing having a chamber and a contained impeller, a spring for moving said impeller in one direction, a lever pivoted in said casing with one arm operatively connected to said impeller for moving the same in the other direction, independently operable mechanically and manually operable means engageable with the other arm of said lever for swinging the same in a direction that will move said impellerin said other direction, said mechanically operable means comprising a rotary cam engaging said other arm of said lever, and said manually operable means comprising a member reciprocable in said casing transversely of the axis of said lev'er with its outer end portion located exteriorly of said casing and with its inner end portion extending loosely through an opening provided therefor in said other arm of said leverv and terminating in a head larger than said opening adapted to swing said lever in said direction when said member is l pulled outwardly in said opening, and a spring mountedin said casing for urging said other arm in the direction ot said head of said member and 5 in the direction of said cam.

HERBERT C. EDWARDS. 

